Techniques for the production of hybridomas and monoclonal antibodies are well known. All such techniques require the immunization of a lymphocyte against a preselected antigen. In many cases, especially those involving lymphocytes of non human origin, the immunization can be carried out by classical injection of the antigen into an immuno-competent host animal, followed eventually by sacrificing the animal and removing the spleen which is a fertile source of immune lymphocytes.
With increasing interest in human monoclonal antibodies, it has become necessary to devise ways of immunizing human lymphocytes in-vitro.
Hoffmann discloses a process for producing human B-lymphocytes comprising culturing human B-lymphocytes in a tissue culture medium in the presence of an antigen, helper signal producing agents comprising monocytes or monocyte conditioned medium containing Interleuken 1, helper T-lymphocytes or helper T-lymphocyte replacing factor, and homologous human serum, followed by recovering the antibody producing cells from the medium. [U.S. Pat. No. 4,444,887 issued Apr. 24, 1984 from an application filed Mar. 12, 1981.]
Cavagnaro and Osband (Biotechniques, 1, pp. 30-36 (1983)) disclose a method for the in vitro primary immunization of human peripheral blood mononuclear cells. The method requires three steps: (1) use of autologous serum (autologous with cultures; (2) depletion of suppressor lymphocytes bearing H2 histamine receptors from human peripheral blood monocyte source; and (3) use of non-specific lymphocyte activator in the immunizing cultures.
Erisman et al. describe the presence of bombesin in a human lung small-cell carcinoma grown in nude mice. Bombesin is a tetradecapeptide initially isolated from frog skin. [P.N.A.S. (USA) 79, pp. 2379-2383, (1982).]
Moody et al. disclose the bombesin levels in small cell lung, but not other types of human cancer, are routinely elevated. [Peptides, Vol. 4 pp. 683-686 (1983).]